Rockwell Automation Publication 2080-UM004C-EN-E - March 2015
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High Speed Counter – 2080-MOT-HSC
Appendix
4
Quadrature Counter (X1)
The module is compatible with 2 and 3 signal quadrature, or incremental
encoders. The A and B signals are offset by 90 degrees and encode the direction of
the rotation. The third signal, Z, occurs once per revolution and is often used as a
home reference. The module’s use of this signal is discussed below in the Z input
section.
INPUT A
INPUT B
INPUT Z
Increment Pulse
(Input A)
Count Pulse
(Input A)
1
2
3
2
1
0
0
1
Increment Pulse
(count up)
Decrement Pulse
(count down)
Incrementing
Encoder or Sensor
Decrementing
Encoder or Sensor
Present Count
Up/Down Counting
A
B
Change in Count Value
0 or 1
+1
0 or 1
-1
0
0
0
0
